If a 4-digit UN number is observed on the scene, which color-bordered ERG section provides initial guidance?

If a 4-digit UN number is observed on the scene, which color-bordered ERG section provides initial guidance?

• A. Blue-bordered material index section
• B. Yellow-bordered section
• C. Orange-bordered section
• D. Green-bordered section

Answer: (B)

When you spot a four-digit UN number, you use the yellow-bordered section of the ERG as your first guide. That part of the book is organized by UN number and provides the initial emergency response information for that material, including the hazards to expect, the protective actions to take, the recommended PPE, and any necessary isolation distances. The UN number is a universal identifier that lets responders jump straight to the relevant guidance without needing to know the exact product name. The other color sections cover different types of information (more detailed or specialized guidance), but for starting actions based on a UN number, the yellow section is where you begin.

When you spot a four-digit UN number, you use the yellow-bordered section of the ERG as your first guide. That part of the book is organized by UN number and provides the initial emergency response information for that material, including the hazards to expect, the protective actions to take, the recommended PPE, and any necessary isolation distances. The UN number is a universal identifier that lets responders jump straight to the relevant guidance without needing to know the exact product name. The other color sections cover different types of information (more detailed or specialized guidance), but for starting actions based on a UN number, the yellow section is where you begin.